1. Field of the Invention
This invention relates generally to electrical motors and more particularly to an apparatus for winding rotors for such motors.
2. Background Description
In accordance with German Pat. No. 21 02 354 and U.S. Pat. Nos. 3,878,602 and 3,924,816, a multiple winding apparatus for motor rotors is known, wherein a rotor support has vertically located bores with bushings, into which the rotors may be set with their shaft end facing away from the collector. In the winding position, the rotors are pressed against locating ribs as soon as clamping heads are moved into their effective positions, wherein a spring-loaded ball is provided in the clamping head, the ball pressing into one of the grooves. The clamping heads are provided on their forward frontal surface with a recess, each adapted to the circumferential surface of the rotor packs. The recesses extend to the rotor grooves into which the wire is to be wound with the rotor being stationary, while the remaining parts adjacent to the recess of the frontal surface are shaped by beveling or rounding into guide surfaces, the so-called winding templates, for the wire to be wound. Each of the clamping heads is bearingly supported on a shaft, with the shaft being provided at its end facing the clamping head with a winding arm, each consisting of a wire strap with a guide roller at its free end. During the rotation of the shafts, the guide rollers move on a circular path, thereby winding the wires into the rotor grooves. The switching and alignment of the rotors is effected by means of a pawl engaging the grooves with a nose.
However, the winding apparatus is relatively complicated, in particular because as the winding arms are not adjustable, the introduction of the wire to form the individual coils cannot be controlled and furthermore the apparatus is less suitable for extremely small rotors, as longer stops cannot be avoided in case of extremely short winding cycle times.
Multiple coil winding machines are known for example from U.S. Pat. No. 4,635,865 and Swiss Pat. No. 01786/85-0 for the winding in layers of electrical coils. To be able to wind the great variety of different coil forms in winding machines of this type, the movement of the wire guides and the wire cutting device is displaceable in the X, Y and Z axes, with the wire cutting devices being additionally displaceable relative to the wire guide and also rotatable around their own vertical axis, while being capable of tilting, together with the wire guides. This also assures that the coil wire ends may be applied to all possible connecting elements automatically, exactly and rapidly. The connecting elements may be positioned radially, axially, unilaterally or bilaterally relative to the coil. The coils are wound by rotating the coils set into the winding tool around the axis of the winding tool, while the wire guide merely carries out an advance motion for the clean winding of the individual layers. This makes very high winding velocities possible whereby time losses may be kept very low, even with very short winding cycles.
British Pat. No. 919 652 and German Pat. No. 12 63 159 disclose rotor winding machines wherein the rotor is gripped by a clamping device, whereby the guide surfaces of the guide body make certain that the wire coming from the supply roll is being guided into the grooves to be wound. In the process, the rotor turns with its axis perpendicular to the winding axis, and for the winding of the next layer the anchor is rotated further by a groove division, while the winding tool is stationary. In the British patent, fixation in the prevailing winding position is effected by means of a spring-loaded spherical catch pressing into the gap of a groove. To switch the rotor for the next winding, an angle hook presses against the edge of a groove and rotates the rotor if a key is depressed by one groove division. In these known winding machines the wire is introduced by the aforementioned guide surfaces into the groove, but it is not wound cleanly in layers.
The foregoing illustrates limitations known to exist in present devices. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.